Leaf spring arrangement for color selection electrode

ABSTRACT

A color cathode-ray tube which is provided with leaf springs for supporting a color selection electrode, such as a shadow mask or lattice-shaped grid, within the tube.

United States Patent [72] Inventors Eiichi Yamamki Ichihara; iiiromi Kanai, Mobara, both of Japan [21 Appl. No. 28,472

[22] Filed Apr. 14, 1970 [45] Patented Oct. 5, I971 [73] Assignee Hitachi, Ltd.

Tokyo, Japan [32] Priority Apr. 18, 1969 [54] LEAF SPRING ARRANGEMENT FOR COLOR SELECTION ELECTRODE 3 Claims, 4 Drawing Figs.

[52] U.S. Cl 313/85, 313/284 [51] Int. Cl H01) 1/96, HOlj 19/50, HOlj 29/46 -[50] FieldoiSeareh Mil/85,85 SH, 64, 65, 92 BS, 283, 284, 292

[56] Reterences Cited UNITED STATES PATENTS 2,755,405 7/1956 Wilhelm 313/92 3,296,477 lll967 Shrader' et al 313/85 3,404,302 10/1968 Nicklas 313/85 Primary ExaminerRoy Lake Assistant Examiner-V. Lafranchi Attorney-Craig, Antonelli & Hill ABSTRACT: A color cathode-ray tube which is provided with leaf springs for supporting a color selection electrode, such as a shadow mask or lattice-shaped grid, within the tube.

LEAF SPRING ARRANGEMENT FOR COLOR SELECTION ELECTRODE BACKGROUND OF THE INVENTION Field Of The Invention The present invention relates to the structure of a cathoderay tube and more particularly to improvements in the leaf spring for supporting the color selection electrode, such as the shadow mask or lattice-shaped grid, within the tube.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a front elevation, partially broken away, of a conventional color cathode-ray tube.

FIG. 2 is a perspective view of the leaf spring for supporting the color selection electrode in the cathode-ray tube of FIG. 1.

FIG. 3 is a diagrammatical view showing the deformation of the leaf spring, with the color selection electrode mounted thereon.

FIG. 4 is a diagrammatical view showing an embodiment of the leaf spring in the color cathode-ray tube according to the present invention.

DESCRIPTION OF THE PRIOR ART As shown in FIG. I, a color cathode-ray tube includes a color selection electrode I consisting of a shadow mask or lattics-shaped grid (hereinafter referred to as shadow mask I), which is positioned along the inner surface of the bulb face 2 with a suitable space between it and the fluorescent layer 3, and supported by projecting studs (not shown) by way of a plurality of shadow mask supporting leaf springs 5 connected to a support frame 4.

The leaf spring 5 is required to have a large strength against shock to the body of the cathode-ray tube, so as to hold the shadow mask I in such a manner as to maintain the suitable space between it and tube face 2.

However, a conventional spring 5 has its intermediate portion 6 shaped flat as shown in FIG. 2, so that, when it is used to support the shadow mask I along the inner surface of the tube face 2, the intermediate portion 6 is bent with the concaved surface facing the shadow mask 1, as shown in FIG. 3. Therefore, the conventional spring has the drawback that it is weak in its ability to flex under a force in the direction of the arrow A and permits a slight displacement of the shadow mask 1, when subjected to a shock, causing degradation of the color purity of the color cathode-ray tube. In the embodiment of FIG. 3, a plurality of leaf springs 5 are secured to projecting stud 11 provided in flange of theface plate 2 at one end thereof and are welded to the shadow mask at the other therefore. The plurality of holes provided in the selection electrode 1 are identified by reference numeral 12.

SUMMARY OF THE INVENTION The present invention aims to obviate the drawback mentioned above and to minimize the degradation of color purity by increasing the strength of the leaf spring and thereby positively maintaining the relative position of the shadow mask and the fluorescent layer 3. In the color cathode-ray tube according to the present invention, each of the leaf springs used for supporting the shadow mask is so shaped that the intermediate portion thereof will be bent with the convexed surface facing the shadow mask, when it supports the shadow mask. Therefore, the strength of the leaf spring is increased and the degradation of color purity can be minimized, which is of great practical advantage.

DESCRIPTION OF THE PREFERRED EMBODIMENT figuration so that it may be bent with the convexed surface facing the shadow mas when the leaf spring supports the shadow mask.

Therefore, in the condition wherein the leaf spring 7 supports the shadow mask along the inner surface of the bulb face 2, the said leaf spring 7 is bent as indicated by the two-dot chain lines, with the convexed surface thereof facing the shadow mask. Moreover, since the end portion 9 of the leaf spring 7 is held in contact with the support frame 4, the effective length of the leaf spring 7 is shortened by the length of the leaf spring which is in contact with the said support frame.

Thus, the strength of the leaf spring 7 against flexion under a force in the direction of the arrow B can be improved.

I claim:

I. In a color cathode-ray tube including a color selection electrode positioned adjacent a color screen within a tube envelope, means for supporting said color selection electrode comprising a plurality of leaf springs each secured to a projecting stud provided in a flange of a face plate of said tube envelope at one end thereof and to said color selection electrode at the other end thereof, each leaf spring being disposed in the space between said color selection electrode and said tube envelope and having a convex portion intermediate its ends, said convex portion facing said color selection electrode.

2. The combination defined in claim 1, wherein each of said leaf springs is circumferentially disposed with respect to said color selection electrode.

3. The combination defined in claim 1, wherein said one end of each leaf spring which is secured to a projecting stud is a straight portion integrally connected to said intermediate convex portion by a bend which directs said one end toward the convex surface of said spring. 

1. In a color cathode-ray tube including a color selection electrode positioned adjacent a color screen within a tube envelope, means for supporting said color selection electrode comprising a plurality of leaf springs each secured to a projecting stud provided in a flange of a face plate of said tube envelope at one end thereof and to said color selection electrode at the other end thereof, each leaf spring being disposed in the space between said color selection electrode and said tube envelope and having a convex portion intermediate its ends, said convex portion facing said color selection electrode.
 2. The combination defined in claim 1, wherein each of said leaf springs is circumferentially disposed with respect to said color selection electrode.
 3. The combination defined in claim 1, wherein said one end of each leaf spring which is secured to a projecting stud is a straight portion integrally connected to said intermediate convex portion by a bend which directs said one end toward the convex surface of said spring. 